Lucifer

The Lucifer (無尽剣：ルシフェル) is a sword-summoning apparatus which appears in Devil May Cry 4, and is obtained from Berial's Hell Gate, which it was used to power. It is a hellish weapon worn like a backpack, and is able to spawn a countless number of spectral swords to hover around it. These swords can be rearranged, thrown, or wielded, and will explode either after a short duration, at a command from Dante such as a clap or throwing the rose held in his mouth, or once fifteen more blades have been spawned. It is wielded by Dante during the game.

Background
Lucifer (lit. "Light Bearer" in Latin) is the title of a Babylonian king interpreted in Christian mythology to have been the name of Satan before his fall. Berial is sometimes considered to be his father or son.

Trivia

 * The scene in which Dante acquires the Lucifer is set to Flamenco music and has Dante making sexual innuendo while planting Lucifer's swords in the Hell Gate. It ends with Dante detonating the thrown swords to leave the Hell Gate in the shape of a heart, and then detonating one in the middle with the rose to make the heart split in half. This theme continues on with the named attacks of the weapon, which are derived from sexual terms, primarily those of BDSM.
 * The use of Lucifer has similarities with a few of Vergil's Summoned Swords moves.
 * Dante's character model shows him having a rose in his mouth, like in the cutscene when you got this weapon.